Lincoln's assassin was John Wilkes Booth, a popular actor from a famous theatrical family.  The Booth family owned slaves at their Maryland home, and young Booth considered slavery to be a blessing for both the white owners and the black slaves.  When the Civil War began, Wilkes Booth made no secret of his support of the Confederate cause and his disdain for the Union's president, Abraham Lincoln.  However, he did not volunteer for Confederate military duty, which he claimed was at his mother's request.

During the Civil War, Booth continued his successful acting career, while criticizing Lincoln and his war policies.  In 1864, Booth's anger built as he suffered from chronic laryngitis and lost money investing in oil wells.  His frenzied concern for the Confederate cause escalated in the fall of that year as Atlanta fell to the Union and Lincoln was reelected.  In reaction, Booth conferred with Confederate spies and hatched a scheme to kidnap Lincoln in order to exchange him for Confederate prisoners of war.  (There is no evidence that Confederate officials approved or even knew of the kidnapping plot.)

Booth recruited several accomplices:  Samuel Arnold, Michael O'Laughlin, George Atzerodt, John Surratt, Lewis Paine, and David Herold.  The conspirators met at an inn and boardinghouse owned by Surratt's mother, Mary Surratt, whose knowledge of the scheme is uncertain.  Booth's first plan to kidnap the president while he attended the theater proved too impractical, so they settled on the idea of nabbing him as he rode outside Washington, D.C.  The date was set for March 17, 1865, when Lincoln would be driven out of the capital to attend a play at a hospital.  The ploy fell through when the president cancelled at the last minute.

Booth had already begun to consider assassination instead of kidnapping when he attended Lincoln's second inauguration on March 4, 1865.  After the abduction fizzled, Booth began drinking heavily (like his alcoholic father) and increasingly saw himself as a savior for the South, as the Brutus who would kill the tyrannical Caesar.  

The final decision came when Booth heard Lincoln deliver an address on the White House lawn on April 11.  The president's lenient (wartime) Reconstruction policy had come under intense fire from the Radical wing of his party.  In the speech that evening, Lincoln made major concessions to the Radicals, acknowledging Congress's legitimate role in the process and expressing hope that voting rights would be given to blacks who were educated or Union veterans. That was the last straw for Booth.  He turned to Paine and ordered him to shoot the president, but the younger man refused.

If the deed were to be done, Booth realized that he must do it.  Although Lee had already surrendered to Grant, Confederate president Jefferson Davis was still on the run (and wanting to continue the war) and Confederate general Joseph Johnston had not surrendered.  Booth believed that the assassination of Lincoln, Vice President Andrew Johnson, and Secretary of State William Seward would destabilize the Union and give new life to the Confederate cause.  Only three of the conspirators, though, would go along with the plan--Herold, Paine, and Atzerodt--and the latter only reluctantly after a harangue from Booth.

At noon on April 14, 1865, Booth learned that the Lincolns would be attending a performance of Our American Cousin that evening at Ford's Theatre.  Atzerodt was assigned to kill Johnson, Paine (with Herold's assistance) to murder Seward, while Booth would take out the president; all at 10:15 p.m.  Lincoln's advisors begged the president not to attend the theater.  Mary Lincoln developed a severe headache and tried to dissuade her husband, but he wanted an evening of relaxation.  Since it was Good Friday, and because many other political wives disliked Mrs. Lincoln, they had difficulty finding another couple to join them.  Finally, Clara Harris, the daughter of Senator Ira Harris of New York, and Major Henry Rathbone, her fiancé and step-brother, agreed to attend.

When Lincoln's theater party arrived, the play had already begun, but the conductor interrupted the actors and directed the orchestra in "Hail to the Chief," as the audience applauded and cheered.  A smiling Lincoln bowed gratefully to the audience.  Since Booth was a prominent actor, he had no difficulty in gaining admittance.  He walked swiftly to the president's box, where the policeman assigned to protect Lincoln had left his post, leaving only a White House usher to whom Booth presented his card and was allowed to enter.  He bolted the door behind him and at 10:13 p.m., when the audience was reacting to one of the play's biggest laugh-lines, Booth stepped up behind Lincoln and pulled the trigger.  As the president slumped over, Rathborne grabbed at Booth, but the assassin cut the major's arm, severing an artery.  Booth then leapt to the stage, catching his spur on a flag and breaking his leg.  He shouted:  "Sic semper tyrannis!" ("Thus always to tyrants", the state motto of Virginia) and made his escape.

Lincoln lingered without gaining consciousness and died at 7:22 a.m. on April 15.  Upon learning the news, a tearful Secretary of War Edwin Stanton replied, "Now he belongs to the ages."  Atzerodt had not gone through with an attempt on Johnson's life, while Paine wounded Seward and his son, though both survived.  

Herold met up with Booth and took him to Dr. Samuel Mudd's home where the physician set the assassin's broken leg.  On April 26, federal authorities captured Herold at a farm near Port Royal, Virginia, but Booth refused to surrender.  The barn in which he was hiding was set afire, and Sergeant Boston Corbett finally shot him to death.  Except for John Surratt who escaped to Canada, the other alleged conspirators were arrested, tried by a military court, and found guilty.  Atzerodt, Herold, Paine, and Mrs. Surratt were hanged on July 7, 1865.  Arnold, Mudd, and O'Laughlin received life sentences.  In 1867, Surratt was captured, tried by a civil court, and freed when the jury deadlocked.  O'Laughlin died in jail, but President Johnson pardoned Arnold and Mudd in 1869.